Conventional control systems employ an industrial programmable controller, known as a PLC (Programmable Logic Controller) and the program written for the specific control application. These programs are generated using low-level machine code type language editors or higher level editors which often provide a graphical platform for linking aspects of the system.
Common repeatable functions can be utilised in both cases by using paramaterisable routines, with each instance use of the function represented by a call of the function to carry out required examination or operation on the items specified by the parameters assigned to the call of the function. The advantage of this is that the routine code does not require full testing and validation in each call instance.
Conventional PLC code generation, therefore, is accomplished using either low level or high level editors. While it might appear that some of the high level editors do not produce PLC code, such editors will produce code which itself compiles to produce the PLC code.